# Grand Slam Titles Problem

## Description

LeetCode Problem 1783.

Table: Players

``````1
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+----------------+---------+
| Column Name    | Type    |
+----------------+---------+
| player_id      | int     |
| player_name    | varchar |
+----------------+---------+
player_id is the primary key for this table.
Each row in this table contains the name and the ID of a tennis player.
``````

Table: Championships

``````1
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+---------------+---------+
| Column Name   | Type    |
+---------------+---------+
| year          | int     |
| Wimbledon     | int     |
| Fr_open       | int     |
| US_open       | int     |
| Au_open       | int     |
+---------------+---------+
year is the primary key for this table.
Each row of this table containts the IDs of the players who won one each tennis tournament of the grand slam.
``````

Write an SQL query to report the number of grand slam tournaments won by each player. Do not include the players who did not win any tournament.

Return the result table in any order.

The query result format is in the following example:

``````1
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Players table:
+-----------+-------------+
| player_id | player_name |
+-----------+-------------+
| 2         | Federer     |
| 3         | Novak       |
+-----------+-------------+

Championships table:
+------+-----------+---------+---------+---------+
| year | Wimbledon | Fr_open | US_open | Au_open |
+------+-----------+---------+---------+---------+
| 2018 | 1         | 1       | 1       | 1       |
| 2019 | 1         | 1       | 2       | 2       |
| 2020 | 2         | 1       | 2       | 2       |
+------+-----------+---------+---------+---------+

Result table:
+-----------+-------------+-------------------+
| player_id | player_name | grand_slams_count |
+-----------+-------------+-------------------+
| 2         | Federer     | 5                 |
| 1         | Nadal       | 7                 |
+-----------+-------------+-------------------+

Player 1 (Nadal) won 7 titles: Wimbledon (2018, 2019), Fr_open (2018, 2019, 2020), US_open (2018), and Au_open (2018).
Player 2 (Federer) won 5 titles: Wimbledon (2020), US_open (2019, 2020), and Au_open (2019, 2020).
Player 3 (Novak) did not win anything, we did not include them in the result table.
``````

## MySQL Solution

``````1
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select player_id, player_name,
sum((if(Wimbledon = player_id,1,0) +
if(Fr_open = player_id,1,0) +
if(US_open = player_id,1,0) +
if(Au_open = player_id,1,0))) as grand_slams_count
from Players inner join Championships
on Wimbledon = player_id or Fr_open = player_id or US_open = player_id or Au_open = player_id
group by player_id
``````